IPN, Orsay
INFN/LASA, Segrate (MI)
SCK-CEN, Mol
CEA, Gif-sur-Yvette
IAP, Frankfurt am Main
An Accelerator Driven System (ADS) for transmutation of nuclear waste typically requires a 600 MeV - 1 GeV accelerator delivering a proton flux of a few mA for demonstrators, and a few tens of mA for large industrial systems. Such a machine belongs to the category of the high-power proton accelerators, with an additional requirement for exceptional "reliability": because of the induced thermal stress to the subcritical core, the number of unwanted "beam-trips" should not exceed a few per year, a specification that is far above usual performance. This paper describes the reference solution adopted for such a machine, based on a so-called "fault-tolerant" linear superconducting accelerator, and presents the status of the associated R&D. This work is performed within the 6th Framework Program EC project "EUROTRANS".
GSI, Darmstadt
ORNL, Oak Ridge, Tennessee
IAP, Frankfurt am Main
CEA, Gif-sur-Yvette
Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 ‘‘Structuring the European Research Area’’ program (CARE, Contract No. RII3-CT-2003-506395).
Beam dynamics experiments with high intensity beams have been conducted at the GSI UNILAC in 2006-2008 with the goal of benchmarking four major simulation codes, i.e. DYNAMION, PARMILA, TraceWin/PARTRAN and LORASR with respect to transverse emittance growth along a DTL. The experiments comprised measurements of transverse phase space distributions in front of as well as behind the DTL. Additional longitudinal bunch length measurements at the DTL entrance allowed for estimate and control of mismatch in all three planes. Measured effects of mismatch and of theoretically predicted space charge resonances (equipartitioning and others) are compared with simulations for a wide range of transverse phase advance along the DTL. This contribution is the first report on the successful measurement of a space charge driven fourth order resonance in a linear accelerator.
CEA, Gif-sur-Yvette
INFN/LNL, Legnaro (PD)
During the EVEDA (Engineering Validation and Engineering Design Activities) phase of the IFMIF (International Fusion Materials Irradiation Facility) project, a 125 mA/9 MeV accelerator prototype will be built, tested and operated in Rokkasho-Mura (Japan). The injector section of this accelerator is composed by an ECR source, delivering a 140 mA deuteron beam at 100 keV, and a low energy beam transport (LEBT) line required to match the beam for the RFQ injection. The proposed design for the LEBT is based on a dual solenoids focusing scheme. In order to takes into account the space charge compensation of the beam induced by the ionisation of the residual gas, a 3D particle-in-cell code (SOLMAXP) has been developed for the beam dynamics calculations. The LEBT parameters have been optimized in order to maximize the beam transmission through the RFQ. The final LEBT design, as well as the simulation results, are presented.
CEA, Gif-sur-Yvette
The 250 mA, 40 MeV cw deuteron beam required for the International Fusion Materials Irradiation Facility (IFMIF) will be provided by two 125 mA linacs. In order to accelerate the beam from 5 MeV to 40 MeV, a superconducting linac, housed in four cryomodules, is proposed. The design is based on two beta families (beta=0.094 and beta=0.166) of half-wave resonators (HWR) at 175 MHz. The transverse focusing is achieved using one solenoid coil per lattice. This paper presents the extensive multi-particle beam dynamics simulations that have been performed to adapt the beam along the SC-HWR structure in such a high space charge regime. As one of the constraints of the IFMIF linac is hands-on maintenance, specific optimizations have been done to minimize the beam occupancy in the line (halo). A Monte Carlo error analysis has also been carried out to study the effects of misalignments or field imperfections.
CEA, Gif-sur-Yvette
INFN/LNL, Legnaro (PD)
CIEMAT, Madrid
The two IFMIF (International Fusion Materials Irradiation Facility) accelerators will each have to deliver 5 MW of deuteron beam at 40 MeV. To validate the conceptual design, a prototype, consisting of one 9 MeV accelerator called EVEDA (Engineering Validation and Engineering Design Activity), is being constructed. Beam dynamics studies are entering the final phase for the whole EVEDA and for the accelerating part of IFMIF. The challenging point is to be able to reconcile the very strong beam power and the hands-on maintenance constraint. At energies up to 5 MeV, difficulties are to reach the requested intensity under a very strong space charge / compensation regime. Over 5 MeV, difficulties are to make sure that beam losses can be maintained below 10-6 of the beam intensity. This paper will report the strategies and choices adopted in the optics design and the beam measurement proposal.